Dataset Information

Exposure to metal mixtures in relation to blood pressure among children 5-7 years old: An observational study in Bangladesh.

ABSTRACT: Hypertension in later life, a significant risk factor for cardiovascular disease, has been linked to elevated blood pressure in early life. Exposure to metals may influence childhood blood pressure; however, previous research is limited and has mainly focused on evaluating the toxicity of single metal exposures. This study evaluates the associations between exposure to metal mixtures and blood pressure among Bangladeshi children age 5-7 years.

Methods

We investigated the associations of 17 toenail metal concentrations with blood pressure using linear regression models. Principal component analysis (PCA), weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) were conducted as secondary analyses.

Results

Associations were observed for selenium with diastolic blood pressure (per doubling of exposure β = 2.91, 95% confidence interval [CI] = 1.08, 4.75), molybdenum with systolic (β = 0.33, 95% CI = 0.05, 0.61) and diastolic blood pressure (β = 0.39, 95% CI = 0.12, 0.66), tin with systolic blood pressure (β = -0.33, 95% CI = -0.60, -0.06), and mercury with systolic (β = -0.83, 95% CI = -1.49, -0.17) and diastolic blood pressure (β = -0.89, 95% CI = -1.53, -0.26). Chromium was associated with diastolic blood pressure among boys only (β = 1.10, 95% CI = 0.28, 1.92, P for interaction = 0.02), and copper was associated with diastolic blood pressure among girls only (β = -1.97, 95% CI = -3.63, -0.32, P for interaction = 0.01). These findings were largely robust to the secondary analyses that utilized mixture modeling approaches (PCA, WQS, and BKMR).

Conclusions

Future prospective studies are needed to investigate further the impact of early life exposure to metal mixtures on children's blood pressure trajectories and cardiovascular disease risk later in life.

SUBMITTER: Shih YH

PROVIDER: S-EPMC7939402 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundChild blood pressure (BP) is predictive of future cardiovascular risk. Prenatal exposure to metals has been associated with higher BP in childhood, but most studies have evaluated elements individually and measured BP at a single time point. We investigated impacts of prenatal metal mixture exposures on longitudinal changes in BP during childhood and elevated BP at 11 years of age.MethodsThe current study included 176 mother-child pairs from the Rhea Study in Heraklion, Greece and focused on eight elements (antimony, arsenic, cadmium, cobalt, lead, magnesium, molybdenum, selenium) measured in maternal urine samples collected during pregnancy (median gestational age at collection: 12 weeks). BP was measured at approximately 4, 6, and 11 years of age. Covariate-adjusted Bayesian Varying Coefficient Kernel Machine Regression and Bayesian Kernel Machine Regression (BKMR) were used to evaluate metal mixture impacts on baseline and longitudinal changes in BP (from ages 4 to 11) and the development of elevated BP at age 11, respectively. BKMR results were compared using static versus percentile-based cutoffs to define elevated BP.ResultsMolybdenum and lead were the mixture components most consistently associated with BP. J-shaped relationships were observed between molybdenum and both systolic and diastolic BP at age 4. Similar associations were identified for both molybdenum and lead in relation to elevated BP at age 11. For molybdenum concentrations above the inflection points (~ 40-80 μg/L), positive associations with BP at age 4 were stronger at high levels of lead. Lead was positively associated with BP measures at age 4, but only at high levels of molybdenum. Potential interactions between molybdenum and lead were also identified for BP at age 11, but were sensitive to the cutoffs used to define elevated BP.ConclusionsPrenatal exposure to high levels of molybdenum and lead, particularly in combination, may contribute to higher BP at age 4. These early effects appear to persist throughout childhood, contributing to elevated BP in adolescence. Future studies are needed to identify the major sources of molybdenum and lead in this population.

Project description:BackgroundStudies have evaluated environmental exposure to toxic metals such as arsenic (As), cadmium (Cd), manganese (Mn), or lead (Pb) on birth size; however, information on potential effects of exposures to metal mixtures is limited.ObjectivesWe assessed the association between metal mixtures (As, Cd, Mn, Pb) in umbilical cord blood and neonate size in Bangladeshi children.MethodsIn this birth cohort study, pregnant women who were ≥18 years of age with an ultrasound-confirmed singleton pregnancy of ≤16wk gestation were recruited from two Bangladesh clinics between 2008 and 2011. Neonate size metrics were measured at the time of delivery. Metals in cord blood were measured using inductively coupled plasma mass spectrometry. We employed multivariable linear regression and Bayesian kernel machine regression (BKMR) to estimate associations of individual metals and metal mixtures with birth size parameters.ResultsData from 1,088 participants was assessed. We found a significant negative association between metal mixture and birth length and head circumference when all metal concentrations were above the 60th and 55th percentiles, respectively, compared with the median. An interquartile range (IQR) increase in log Cd concentration {log[Cd (in micrograms per deciliter)] IQR=2.51} was associated with a 0.13-standard deviation (SD) decrease in mean birth length (95% CI: -0.25, -0.02) and a 0.17-SD decrease in mean head circumference (95% CI: -0.28, -0.05), based on linear regression models adjusted for covariates and the other metals. An IQR increase in log Mn concentration {log[Mn (in micrograms per deciliter)] IQR=0.69} was associated with a 0.07-SD decrease in mean birth weight (95% CI: -0.15, 0.002).DiscussionMetal mixtures in cord blood were associated with reduced birth size in Bangladeshi children. Results from linear regression models adjusted and the BKMR mixtures analyses suggest adverse effects of Cd and Mn, as individual metal exposures, on birth size outcomes. https://doi.org/10.1289/EHP7502.